<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>三栏布局</title>
    <!-- 
        优点：简单，兼容性好
        缺点：脱离文档流
     -->
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .wrap{
            position: relative;
        }
        .left,.right,.center{
            position: absolute;
            min-height: 200px;
            top: 0;
        }
        .left{
            left: 0;
            width: 300px;
            background-color: red;
        }
        .right{
            right: 0;
            width: 200px;
            background-color: skyblue;
        }
        .center{
            left: 300px;
            right: 200px;
            background-color: orange;
        }
    </style>
</head>
<body>
    <div class="wrap">
        <div class="left"></div>
        <div class="right"></div>
        <div class="center"></div>
    </div>
</body>
</html>